[Expression and significance of Shh and Wnt5a genes in Cornelia de Lange syndrome].

OBJECTIVE: To study the expression of Shh and Wnt5a genes in the limb buds of NIPBL+/- fetal rats and the association of these two genes with Cornelia de Lange syndrome (CdLS). METHODS: A total of 72 NIPBL+/- fetal rats were divided into an experimental group and a control group, with 36 rats in each group. The limb buds were collected from 12 fetal rats each on embryonic days 10, 11 and 12 (E10, E11 and E12) respectively. Real-time PCR and Western blot were used to measure the mRNA and protein expression of Shh and Wnt5a. RESULTS: The mRNA and protein expression of Shh and Wnt5a was detected in the limb buds on E10, E11 and E12, and the experimental group had significantly lower expression than the control group (P<0.01). The mRNA and protein expression of Shh and Wnt5a in limb buds was at a low level on E10, followed by an increase on E11 and a reduction on E12, and the expression on E12 was still lower than that on E10 (P<0.01). CONCLUSIONS: The mRNA and protein expression of Shh and Wnt5a are consistent. The pathogenesis of CdLS may be associated with the low mRNA and protein expression of Shh and Wnt5a inhibited by the low expression of NIPBL gene.

[Distribution and composition of organochlorine pesticides in farmland top soils of Anhui Province].

By using ultrasonic method and GC/ECD, this paper analyzed the distribution and composition of 8 kinds of organochlorine pesticides (alpha-HCH, beta-HCH, gamma-HCH, delta-HCH, op'-DDE, pp'-DDD, alpha-endosulfan, and chlorothalonil) in farmland top soils (0-20 cm) in 19 districts of Anhui Province, East China. The total concentration of the pesticides in the top soils ranged from 0 to 23.75 microg x kg(-1), among which, pp'-DDD and gamma-HCH were the major pollutants, with the mean concentration being 13.83 and 13.49 microg x kg(-1), respectively. As compared with the analyses in 1990, the present mean concentration of HCH had an obvious decreasing trend, but was still higher than that in the top soils in other regions of China and in other countries. The mean concentrations of OCPs, HCHs and pp'-DDD in the test top soils were 48.58, 28.64 and 13.83 microg x kg(-1), respectively, not surpassed the first grade level (< 50 microg x kg(-1)) of the China National Soil Environmental Quality Standards (GB 15618-1995), suggesting that the farmland top soils in these districts of Anhui Province were less polluted.